Increasing evidence links sleep disordered breathing (SDB) in children to behavioral disturbances, and to poorer performance in school and on neurocognitive tests. However, the natural history and long-term impact of SDB remains to be determined. The primary objectives of this competitive renewal are to determine the impact of SDB identified in preadolescents on subsequent school and neurocognitive performance, to assess factors, which influence the natural history of SDB in children and to ascertain whether these elements differ between Caucasians and Hispanics. An additional objective is to assess whether previously identified changes in ventilatory drive persist on subsequent evaluation. This project thus proposes a reevaluation of the Tucson Children's Assessment of Sleep Apnea (TuCASA) cohort. This cohort of children initially recruited from ages 6 through 11 years to analyze the prevalence and correlates of childhood SDB, is well characterized, and is an ideal vehicle to achieve the following specific aims: 1) to determine whether SDB in preadolescent children adversely impacts school and neurocognitive performance, growth and blood pressure in these same children approximately 4 years later, and to compare findings between Caucasians and Hispanics;2) to calculate the 4- year incidence and remission rates and current prevalence of SDB in children who were initially studied from ages 6 through 11 years, and to assess whether there are ethnic and/or anthropometric characteristics in preadolescence that influence these rates;3) to assess whether abnormalities previously observed in ventilatory drive persist several years later;4) to determine whether subtle changes in executive and frontal-lobe function can be detected in children who had SDB 4 years previously using a novel test of working memory and sustained attention which incorporates electroencephalographic (EEG) measures obtained during task performance. Approximately 425 children in the TuCASA cohort will undergo a repeat unattended home polysomnogram, neurocognitive test battery, complete questionnaires related to sleep and have selected anthropometric measurements taken approximately 4 years after their initial recruitment. In addition, a subset of 50 children who had ventilatory drive studies during their initial TuCASA evaluation will have these studies repeated. A second sub study will employ a 50 pair case control subset of the TuCASA cohort who were found to have, or not have SDB 4 years previously, but who are matched on age, gender, ethnicity and intelligence. These children will undergo the Sustained Working Memory Task that assesses working memory and sustained attention with concurrent recording of EEG. These data will provide important evidence concerning the long-term impact of SDB on growth and development in children.